Tube



FIG. 1 is a persepctive view of a tube showing my new design;

FIG. 2 is a front view theroef;

FIG. 3 is a back view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a right side elevational view thereof; and,

FIG. 7 is a left side elevational view thereof.

The broken lines in FIG. 1 are for illustrative purposes only and do not form part of the claimed design. 

The ornamental design for a tube, as shown and described. 